Method and Apparatus for Programming and Reading Codes on an Array of Fuses

Abstract

An device for programming and reading codes onto an array of binary data storage element includes: a shift register for receiving, sequentially, a binary data series to be written onto the data storage elements; and control logic circuit for determining whether or not data is to be applied to each of the data storage elements in turn, by reading sequentially the data stored in the shift register and if it is determined that data is to be stored on a respective data element, applying a write signal to that data element. The control logic circuit applies a permanent locking signal to the array of data storage elements such that further writing to the elements is prohibited when it has been determined that data has been written to each of the elements which require data to be written thereto.

1 . An apparatus for programming and reading codes onto an array of binary data storage elements, the apparatus comprising: 
 a shift register for receiving, sequentially, a binary data series to be written onto the binary data storage elements; and    control logic circuit configured to determine whether or not data is to be applied to each of the data storage elements in turn by sequentially reading data stored on the shift register and applying a write signal to a respective data element in response to determining that data is to be stored on the respective data element,    the control logic circuit applying a permanent locking signal to the array of binary data storage elements such that further writing to the binary data storage elements is prohibited in response to determining that data has been written to each of the elements which require data to be written thereto.    
   
   
       2 . An apparatus according to  claim 1 , wherein the control logic circuit sequentially reads the data stored on each of the data storage elements.  
   
   
       3 . An apparatus according to  claim 1 , where each of the data storage elements comprise individual fuses that can be blown to permanently store binary data thereon.  
   
   
       4 . An apparatus according to  claim 3 , wherein the control logic circuit is configured to apply a write signal to a respective data storage element for a predetermined fixed period of time.  
   
   
       5 . An apparatus according to  claim 4 , wherein the control logic circuit is configured to detect whether or not a fuse has blown when a write signal has been applied for the predetermined period of time, and issues an error signal in response to detecting that any of the respective fuses has not blown during the writing process.  
   
   
       6 . A semiconductor chip comprising: 
 said array of binary data storage elements configured to permanently store data indicating the identity of the semiconductor chip;    and the apparatus according to  claim 1.